This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
You can choose whatever way you want. Both are suitable. I think 2nd will be easier to pass ( I did 1st one ;) ).
There are no prerequisites for OCPJP6 and OCAJP7.
You just need to learn, pay and pass one of them ;).
Did you already take the OCPJP5/6 or SCJP? The 1Z0-805 is only to upgrade your cert to version 7. If you are just starting with no cert, you get 1Z0-803 for OCAJP7 and then 1Z0-804 for OCPJP7. Again, 805 only upgrades existing OCPJP5/6 or SCJP, it does not give a fresh cert. I would not bother with option 1.
Could you say us what is your level in Java development ?
If you have no experience, second option is better because the first certification is easier than OCPJP 6 (OCPJP 6 is almost the same knowledge at OCPJP 7, the only difference is the Java's version).
If you have some experience, go to OCPJP6 (because the book of Kathy Sierra is amazing) and ... you have two choice after.
1°) Continue to OCPJP 7 (but I don't think it's a great idea ... OCPJP8 is about to release and there isn't a big difference between java 7 and 6).
2°) Continue to another level of certification like OCEWCD ... until OCPJP8 will be out !
And because Java 8 is coming, OCPJP 8 will be arrived few month or one year after. Java 7 was finished in 2011 and OCPJP 7 was released at the end of 2011. There's just one thing it take a long time, it's the book for OCPJP 8.
There's any bad choice, just make the best choice for you (it depends on your experience and your goal). Maybe, but I don't know (because I did the certification path of Java 6) it's easier to do OCAJP 7 and after OCPJP 7 (because OCPJP 6 is hard )!